Towards super-resolution microwave imaging: General framework

Over past decades, there are growing intensive interests of achieving imaging resolution beyond that mainly constrained to system bandwidth, for example, the so-called Rayleigh diffraction limit. Three directions of research aiming to beat this limit are strongly advocated, i.e., (1) to exploit the evanescent components capturing the subtle details of the electromagnetic field at the immediate proximity of the object to be probed; (2) to develop the imaging algorithm of treating the specific type of imaged object, namely, the sparse object; (3) to design the precise instrument dedicated to create constructive subtle inference. This paper proposed a general framework of super-resolution imaging algorithm, which has the advantages that (a) of highly efficient and can be used for real-time imaging, (b) the sub-wavelength reconstruction, roughly, the resolution can be improved to be the factor of three times compared with the traditional imaging approaches. The key ingredient of proposed methodology is to construct an off-line filter, whose basic function is to produce so-called super-oscillation waves, leading to a sub-wavelength focus of prescribed size and shape in a field of view. Numerical and experimental results have demonstrated the state-of-art performance of the proposed approach, and open a new promising door to real-time super-resolution imaging, regarding computational complexity and imaging resolution.